php - 数据透视表 Laravel 问题

Question

我对 Laravel 中的数据透视表有疑问， 我制作了 customers 和 products 表以及 customer_product 表来连接这两者，但它不起作用。 下面我添加这个数据透视表

    Schema::create('customer_product', function (Blueprint $table) {
        $table->increments('id');
        $table->unsignedInteger('customer_id');
        $table->foreign('customer_id')->references('id')->on('customers');
        $table->unsignedInteger('product_id');
        $table->foreign('product_id')->references('id')->on('products');
        $table->decimal('selling_customer_price');
        $table->decimal('purchase_customer_price'); 
        $table->decimal('consumed_customer_price');
        $table->timestamps();
    });
}

我的 ProductController 的一部分，我在其中列出产品并想向客户展示产品

public function list()
{

    return view('products.list', [
        'customers' => Customer::all(),
        'products' => Product::orderby('name')->get(),

    ]);
}

和部分简单 Blade 代码

<div>
     @foreach ($customers as $customer)
        <li> {{ $customer->name }} {{ $customer->products }} </li>
     @endforeach
</div>

产品类的一部分

public function customers()
{
    return $this->belongsToMany(Customer::class);
}

和客户类的一部分

public function products()
{
    return $this->hasMany(Product::class);
}

当我输入 list site 时，我有关于 product 表中缺少 customer_id 列的错误，但我想使用我的数据透视表，因为我必须对不同的客户使用不同的价格.

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'products.customer_id' in 'where clause' (SQL: select * from products where products.customer_id = 1 and products.customer_id is not null) (View: /home/vagrant/code/resources/views/products/list.blade.php)

Answer 1

你说你有多对多关系，那么你应该有如下关系，从你的评论中，你在数据透视表中有 selling_customer_price 字段，你必须使用 withPivot。详情请查看https://laravel.com/docs/5.6/eloquent-relationships#many-to-many

产品类的一部分

public function customers()
{
    return $this->belongsToMany(Customer::class)->withPivot('selling_customer_price');
}

和客户类的一部分

public function products()
{
    return $this->belongsToMany(Product::class)->withPivot('selling_customer_price');
}

然后像这样获取它

public function list()
{

    return view('products.list', [
        'customers' => Customer::with('products')->all(),
        'products' => Product::orderby('name')->get(),

    ]);
}

在 View 中

<div>
      <ul>
        @foreach ($customers as $customer)
          <li> {{ $customer->name }} </li>
          <ul>
            @foreach ($customer->products as $product)
                <li> {{ $product->name }} </li>
                <li> {{ $product->pivot->selling_customer_price }} </li>
            @endforeach
          </ul>
        @endforeach
     </ul>
</div>